Heat oven to 350 degrees. Grease a 9 x 5 inch loaf pan.
Stir together butter, sugar, peanut butter, and eggs, blend in banana and milk.
Combine flour, baking powder, baking soda and salt. Add to banana mixture; stir just until dry ingredients are moistened .
Fold in raisins and peanuts. Spoon batter into pan.
Bake for 55 - 60 minutes or until toothpick inserted in center comes out clean. Cool in pan 10 minutes. Removed from pan and cool on wire rack